Madam, - Prof James G Lacy's letter of March 13th was headlined "Carbon Emissions and Climate". However, "Can opened, worms everywhere" might have been more apt.
Possibly by coincidence, the claims made by Prof Lacy closely mirror those made in the Channel 4 programme The Great Global Warming Swindle, broadcast on March 8th.
Prof Lacy states that "changes in atmospheric CO2 have followed the increases and decreases in global temperature. So, these CO2 changes are not, as we are being persuaded, the causal factor."
This is a misrepresentation. The lag between the rise in global temperature levels and the subsequent rise in atmospheric CO2 concentrations identified is typically stated to be approximately 800 years. The missing piece of information is that identified periods of warming typically took 5,000 years to complete.
The available data (not just ice-core studies) suggests that, while CO2 levels do not trigger a period of warming, the CO2 levels begin to rise after the time-lag and these increased levels of CO2, being a greenhouse gas, help further increase temperatures, which leads to even further CO2 release - therefore the mechanism is one of feedback and amplification.
Carbon dioxide and other greenhouse gases are not claimed to be the only factors that affect climate. Furthermore the claim is not that human activity is causing global warming - the belief is that human activity is accelerating the process.- Yours, etc,
DANIEL SEXTON, Dublin Road, Blackrock, Dundalk.
Madam, - I know that climate change has been credited with a myriad of adverse future consequences, but it cannot be all that bad if it can result in making Donna Summer and the Three Degrees all of three degrees hotter than they were back in the I970s and 1980s. - Yours, etc,
PAUL WHELAN, Raheen Park, Bray, Co Wicklow.